Ghalgaoui Ahmed, Fingerhut Benjamin P, Reimann Klaus, Elsaesser Thomas, Woerner Michael
Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie, 12489 Berlin, Germany.
Phys Rev Lett. 2021 Mar 5;126(9):097401. doi: 10.1103/PhysRevLett.126.097401.
The terahertz (THz) response of solvated electrons in liquid water is studied in nonlinear ultrafast pump-probe experiments. Free electrons with concentrations from c_{e}=4 to 140×10^{-6} moles/liter are generated by high-field THz or near-infrared multiphoton excitation. The time-resolved change of the dielectric function as mapped by broadband THz pulses exhibits pronounced oscillations persisting up to 30 ps. Their frequency increases with electron concentration from 0.2 to 1.5 THz. The oscillatory response is assigned to impulsively excited coherent polarons involving coupled electron and water shell motions with a frequency set by the local electric field.
在非线性超快泵浦-探测实验中研究了液态水中溶剂化电子的太赫兹（THz）响应。通过高场太赫兹或近红外多光子激发产生浓度范围为(c_{e}=4)至(140×10^{-6})摩尔/升的自由电子。由宽带太赫兹脉冲映射的介电函数的时间分辨变化显示出持续高达30皮秒的明显振荡。其频率随电子浓度从0.2太赫兹增加到1.5太赫兹。这种振荡响应归因于涉及电子与水壳耦合运动的脉冲激发相干极化子，其频率由局部电场设定。
